1. Field of the Invention
This invention relates generally to munitions and more particularly to a bullet which can penetrate body armor and which is suitable for use with a wide range of weaponry, but principally small arms ranging from automatic shoulder arms to hand guns. Ammunition used in peace time law enforcement has certain distinct requirements compared to that required for war time use. It is desirable that ammunition used in populated areas must be both accurate and effective on only the single, intended target. That is, a bullet should not pass through the target to a secondary unintended individual.
2. Description of the Prior Art
Many armor-piercing bullets known in the prior art will easily penetrate body armor, but rely on non-deformation for this performance. Such a design cannot transfer energy effectively, and shows minimum wounding effects with almost guaranteed shoot-through.
The frangible bullets known in the art use the opposite effect and consequently show reverse characteristics. The frangible bullet is designed to break up easily. This provides good energy transfer and wounding capability while reducing the chance of shoot-through. However, body armor or even, in some cases, heavy clothing, will defeat a frangible bullet as its design allows it to break up easily into particles with good energy transfer capabilities, but low penetrative power.
Known frangible bullets are disclosed in U.S. Pat. No. 3,911,820, and No. 3,972,286. The former patent discloses a bullet comprising a hollow missile casing which is attached to a cartridge carrying a propellant charge, wherein the casing holds a plurality of heavy spherical metal particles and a viscous liquid. The casing also has a blunt or rounded tip which forms a frangible seal on the casing. It is stated that such a bullet is resistant to deformation during firing, but the frangible seal breaks upon impact with a target, thereby releasing the contents of the case into the target. The nature of the conical spread of particles from the bullet on penetration into the target is said to be dependent on the viscosity of fluid. Another characteristic of the bullet disclosed is that it does not ricochet off a target which would otherwise occur with previously known small arms projectiles.
U.S. Pat. No. 3,972,286, discloses a bullet which comprises a hollow, open-ended casing which is attached to a cartridge carrying a propellant charge wherein the casing is substantially cylindrical and thereby defines the caliber of the bullet. The casing has a closed base end and encloses a plurality of spherical, shot particles which are freely separable from each other upon impact with a target. The casing further comprises a separate tip which extends into and frangibly seals the open end of the casing.
An integral bullet is constituted which is resistant to deformation or destruction during firing in a rifle bore, but upon impact with a target, the frangible seal breaks, thereby releasing the short particles which scatter separately into the target. It is again stated that an advantage of this particular construction is that the bullet is readily broken upon impact even at low angles, and the bullet will not ricochet off the target. A function of the cap when placed on the open end of the bullet casing is to seal the multiple shot projectiles within the bullet. Also, in order to prevent a very wide spray of shot when the bullet impacts the target, a viscous fluid is required to fill the cavity within the casing of the bullet. This adds an additional incumbrance on a manufacturer preparing the bullets and may also affect the longevity of the bullet given the possibility of fluid leakage from the casing.
These known bullets are said to transfer their energy very rapidly to the target and therefore it is said that they have greater stopping power. In order to achieve this effect, typically some 300 spherical sub-projectiles are used within one bullet casing. It is apparent that such known bullets require many separate components, all of which require individual manufacture prior to assembly of a final integral bullet. In addition, other prior art bullets which can effectively penetrate body armor often shoot entirely through the body, and the armor and thus can cause injury to an unintended target.